<?php

Class GIFEncoder {
	var $GIF = "GIF89a"; /* GIF header 6 bytes        */
	var $VER = "GIFEncoder V2.06"; /* Encoder version                */

	var $BUF = Array();
	var $LOP = 0;
	var $DIS = 2;
	var $COL = -1;
	var $IMG = -1;

	var $ERR = Array(
		'ERR00' => "Does not supported function for only one image!",
		'ERR01' => "Source is not a GIF image!",
		'ERR02' => "Unintelligible flag ",
		'ERR03' => "Could not make animation from animated GIF source",
	);

	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::        GIFEncoder...
	::
	 */
	function __construct(
		$GIF_src, $GIF_dly, $GIF_lop, $GIF_dis,
		$GIF_red, $GIF_grn, $GIF_blu, $GIF_mod
	) {
		if (!is_array($GIF_src) && !is_array($GIF_tim)) {
			printf("%s: %s", $this->VER, $this->ERR['ERR00']);
			exit(0);
		}
		$this->LOP = ($GIF_lop > -1) ? $GIF_lop : 0;
		$this->DIS = ($GIF_dis > -1) ? (($GIF_dis < 3) ? $GIF_dis : 3) : 2;
		$this->COL = ($GIF_red > -1 && $GIF_grn > -1 && $GIF_blu > -1) ?
		($GIF_red | ($GIF_grn << 8) | ($GIF_blu << 16)) : -1;

		for ($i = 0; $i < count($GIF_src); $i++) {
			if (strToLower($GIF_mod) == "url") {
				$this->BUF[] = fread(fopen($GIF_src[$i], "rb"), filesize($GIF_src[$i]));
			} else if (strToLower($GIF_mod) == "bin") {
				$this->BUF[] = $GIF_src[$i];
			} else {
				printf("%s: %s ( %s )!", $this->VER, $this->ERR['ERR02'], $GIF_mod);
				exit(0);
			}
			if (substr($this->BUF[$i], 0, 6) != "GIF87a" && substr($this->BUF[$i], 0, 6) != "GIF89a") {
				printf("%s: %d %s", $this->VER, $i, $this->ERR['ERR01']);
				exit(0);
			}
			for ($j = (13 + 3 * (2 << (ord($this->BUF[$i]{10}) & 0x07))), $k = TRUE; $k; $j++) {
				switch ($this->BUF[$i]{ $j}) {
				case "!":
					if ((substr($this->BUF[$i], ($j + 3), 8)) == "NETSCAPE") {
						printf("%s: %s ( %s source )!", $this->VER, $this->ERR['ERR03'], ($i + 1));
						exit(0);
					}
					break;
				case ";":
					$k = FALSE;
					break;
				}
			}
		}
		GIFEncoder::GIFAddHeader();
		for ($i = 0; $i < count($this->BUF); $i++) {
			GIFEncoder::GIFAddFrames($i, $GIF_dly[$i]);
		}
		GIFEncoder::GIFAddFooter();
	}
	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::        GIFAddHeader...
	::
	 */
	function GIFAddHeader() {
		$cmap = 0;

		if (ord($this->BUF[0]{10}) & 0x80) {
			$cmap = 3 * (2 << (ord($this->BUF[0]{10}) & 0x07));

			$this->GIF .= substr($this->BUF[0], 6, 7);
			$this->GIF .= substr($this->BUF[0], 13, $cmap);
			$this->GIF .= "!\377\13NETSCAPE2.0\3\1" . GIFEncoder::GIFWord($this->LOP) . "\0";
		}
	}
	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::        GIFAddFrames...
	::
	 */
	function GIFAddFrames($i, $d) {

		$Locals_str = 13 + 3 * (2 << (ord($this->BUF[$i]{10}) & 0x07));

		$Locals_end = strlen($this->BUF[$i]) - $Locals_str - 1;
		$Locals_tmp = substr($this->BUF[$i], $Locals_str, $Locals_end);

		$Global_len = 2 << (ord($this->BUF[0]{10}) & 0x07);
		$Locals_len = 2 << (ord($this->BUF[$i]{10}) & 0x07);

		$Global_rgb = substr($this->BUF[0], 13,
			3 * (2 << (ord($this->BUF[0]{10}) & 0x07)));
		$Locals_rgb = substr($this->BUF[$i], 13,
			3 * (2 << (ord($this->BUF[$i]{10}) & 0x07)));

		$Locals_ext = "!\xF9\x04" . chr(($this->DIS << 2) + 0) .
		chr(($d >> 0) & 0xFF) . chr(($d >> 8) & 0xFF) . "\x0\x0";

		if ($this->COL > -1 && ord($this->BUF[$i]{10}) & 0x80) {
			for ($j = 0; $j < (2 << (ord($this->BUF[$i]{10}) & 0x07)); $j++) {
				if (
					ord($Locals_rgb{3 * $j + 0}) == ($this->COL >> 0) & 0xFF &&
					ord($Locals_rgb{3 * $j + 1}) == ($this->COL >> 8) & 0xFF &&
					ord($Locals_rgb{3 * $j + 2}) == ($this->COL >> 16) & 0xFF
				) {
					$Locals_ext = "!\xF9\x04" . chr(($this->DIS << 2) + 1) .
					chr(($d >> 0) & 0xFF) . chr(($d >> 8) & 0xFF) . chr($j) . "\x0";
					break;
				}
			}
		}
		switch ($Locals_tmp{0}) {
		case "!":
			$Locals_img = substr($Locals_tmp, 8, 10);
			$Locals_tmp = substr($Locals_tmp, 18, strlen($Locals_tmp) - 18);
			break;
		case ",":
			$Locals_img = substr($Locals_tmp, 0, 10);
			$Locals_tmp = substr($Locals_tmp, 10, strlen($Locals_tmp) - 10);
			break;
		}
		if (ord($this->BUF[$i]{10}) & 0x80 && $this->IMG > -1) {
			if ($Global_len == $Locals_len) {
				if (GIFEncoder::GIFBlockCompare($Global_rgb, $Locals_rgb, $Global_len)) {
					$this->GIF .= ($Locals_ext . $Locals_img . $Locals_tmp);
				} else {
					$byte = ord($Locals_img{9});
					$byte |= 0x80;
					$byte &= 0xF8;
					$byte |= (ord($this->BUF[0]{10}) & 0x07);
					$Locals_img{9} = chr($byte);
					$this->GIF .= ($Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp);
				}
			} else {
				$byte = ord($Locals_img{9});
				$byte |= 0x80;
				$byte &= 0xF8;
				$byte |= (ord($this->BUF[$i]{10}) & 0x07);
				$Locals_img{9} = chr($byte);
				$this->GIF .= ($Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp);
			}
		} else {
			$this->GIF .= ($Locals_ext . $Locals_img . $Locals_tmp);
		}
		$this->IMG = 1;
	}
	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::        GIFAddFooter...
	::
	 */
	function GIFAddFooter() {
		$this->GIF .= ";";
	}
	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::        GIFBlockCompare...
	::
	 */
	function GIFBlockCompare($GlobalBlock, $LocalBlock, $Len) {

		for ($i = 0; $i < $Len; $i++) {
			if (
				$GlobalBlock{3 * $i + 0} != $LocalBlock{3 * $i + 0} ||
				$GlobalBlock{3 * $i + 1} != $LocalBlock{3 * $i + 1} ||
				$GlobalBlock{3 * $i + 2} != $LocalBlock{3 * $i + 2}
			) {
				return (0);
			}
		}

		return (1);
	}
	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::        GIFWord...
	::
	 */
	function GIFWord($int) {

		return (chr($int & 0xFF) . chr(($int >> 8) & 0xFF));
	}
	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::        GetAnimation...
	::
	 */
	function GetAnimation() {
		return ($this->GIF);
	}
}

?>